Does a suspected perpetrator who is 148 feet away from an officer represent a danger to that officer's life?
Yes. A man of Micheal Brown's size can cover 49 yards quicker than you think. I watch football a lot. I see 300 lb men running 49 yards in less then 15 seconds.
Anyway, you keep ignoring the fact that Brown tried to take Officer Wilson's gun, and at one point tried to kill him with it. Brown's life was forfeit the moment he attempted to kill the police officer.
Also, consider the marksmanship ability of the officer. Do you think he could shoot someone accurately at that distance?
Sigh, and you take this from a bunch of anti-cop, anti-Wilson activists who would otherwise not give two flying ***** about it if this were a white man.